Electric glow-lamp.



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WALTHEB NElR/NST, OF GOTTINGEN,. GERMANY, ASSIGNOR T0 NERNST LAMP COMPANY, CORPORATION OF PENNSYLVANIA.

ELECTRIC GLOW-LAMP.

No Drawing. Original application Specification of Letters Patent.

Patented aa ii, lam.

filed September 10, 1908. eria1No 452,485.

-ment or member is a non-conductor at ordinary temperaturesrand which may be made conductive by subjecting it to a relatively high degree of heat.

The object of my invention is to provide alight emitting member or glowerv of such composition of materials as shall specially adapt it for efiicient service and long life.

I have found that a glower formed of a mixture of certain materials will become conductive at a lower temperature and be more durable in service than a glower made of asingle material, provided the materials are thoroughly powdered and mixed together then combined with a suitable binding material, and formed into the proper shape and thoroughly baked, suitable terminals of conducting material being attached to the ends of the glower in order to facilitate connecting it in circuit for operation.

My invention contemplates the employment of any one of a considerable variety of mixtures of materials, but mixtures of two or more of the oxide of zirconium, yttrium, thorium, beryllium, and magnesium will generally be found most desirable. I may, however, combine one of these oxids, such, for example, as the oxid of magnesium, with a small percentage of boric acid, chlorid of calcium, tungstic acid, or the like.

When a glower formed of a proper mixture of two or more of the materials above specified is connectedin an electric circuit a and heated to its conducting temperature, the heat developed in itself bythe passage of a current therethrough will serve to maintain it in a conducting condition and cause it to yield light in a very eflicient manner.

This application is a division of application, Serial No. 675,603, filed March 29, 1898, which has issued as Patent No. 900,416, and other divisions thereof are Serial No. 848,567, which has issued as Patent No. 1,071,649, and Serial No. 763,184, filed September 24c, 1913.

I claim as my invention:

1. A conductor for electric lamps, consisting of an intimate mixture of yttria and tungstic acid.

2. A light giving body for electric glow lamps which is non-conductive at atmospheric'temperatures and is conductive at high temperatures, consisting of an intimate mixture containing yttria and a small percentage of tungstic acid.

3. A light giving body for electric glow lamps which is non-conductive at atmospheric temperatures and is conductive at high temperatures, consisting of an intimate mixture of the oxid of yttrium and the oxid of tungsten, the former greatly preponderating in quantity.

4:. A glower for incandescent electric Witnesses HENRY HASPER, WOLDEMAR HAUPT. 

